The world population is growing, andmore and more people are moving into the city. In 2050, two thirds of the citizens of the world will live in conurbations. The adaptation of these cities for the future is one of the greatest challenges today. During the 2013 Vienna Tourism Conference, wien.at spoke with climate strategist Boyd Cohen, inventor of the Smart City index, which ranked Vienna as the smartest city worldwide. Cohen talks about abandoned suburbs, full underground trains and why being smart is also clever.

Definition of Terms Martin Schipany: Modern cities are supposed to be "smart," and the term "smart city" is being bandied about all over the media. Is this a fashion trend or something more permanent?Boyd Cohen: A "smart city" is one that exploits technology and innovation to make efficient use of resources and reduce the size of the ecological footprint. This idea is here to stay. The term has a technological origin, but it is also a question of being innovative. What services can be offered to citizens to increase their quality of life? Technology is just one aspect. A high-tech city is not necessarily a smart city. Many urban planners have realized that cities are about people not technology. I don't know whether the term "smart city" will endure. Perhaps it will become "future city" or "innovative city," but the idea is the same.

You illustrate this complex theme with a wheel divided into six segments. Can you explain that to us?I studied existing models for a long time. For example, it was the University of Vienna that produced the first European smart city ranking in 2007. It used the same six categories as I do: environment, living, government, mobility, economy and people. But all the models I have found to date were difficult for the average person to understand. I wanted therefore to develop a more understandable model and chose a simple wheel for that purpose. Each of the six segments in the wheel has three subdivisions containing indicators and actions to enable cities to improve their performance.

As the creator of this wheel, do you believe that it is because of you that technological aspects are now combined with social and economic factors in the definition of a smart city?I don't claim the credit for myself alone. Like many others, I wanted to remove the "smart city" fromthe private technology sector and foster a comprehensive approach. What is a city; who are its customers; and how can "smart cities" benefit people? It's not a question of businesses selling us new services, but rather of what a city should look like in the 21st century.

Sustainability Everything today is moving in the direction of sustainability. Will it continue to do so?Absolutely. We have a rapidly increasing world population, which will grow from the present seven billion to almost ten billion by the year 2100. Added to this is a strong trend towards urbanization with more and more people moving to the cities. There is enormous pressure on the resources of a city: food, energy, water, jobs, etc. We therefore need to use existing resources efficiently. Climate change is also an ongoing challenge. And citizens have become much more active – politically committed or interested in the developments in their city. The public is highly critical in particular when it comes to sustainability.

Calculation Model A few years ago Vienna was number one in the list of smart cities. In the most recent study it had dropped to 4th place. What must Vienna do to gain back the top spot?I should point out at the outset thatmy calculation model has evolved over time. In 2011, I was still working out exactly what a smart city should be. In the original index I used only four categories; now there are six. Vienna has not dropped down because of specific shortcomings but because the calculation model has become more robust. This year there will be new indicators again. For that reason I contacted cities directly to explain measures in connection with 28 further factors required to qualify as a smart city. I should be receiving the replies from Vienna soon.

Best Practice Examples What examples are there of current best practices?Boyd Cohen: With regard to smart economy, there is a need above all to stimulate businesses and innovation. Barcelona is a good example in this regard with its innovative district 22@. In this area start-ups are encouraged to create new jobs in the technology sector. Another example is Singapore, which has always had a shortage of drinking water and was largely dependent on imported water. The city is now concentrating on obtaining and recycling drinking water from rain. Thanks to this technical innovation they now have around 100 companies specializing in water technology. A weakness has been turned into a strength. Copenhagen is also working impressively to make the city CO2-neutral by the year 2025.

Vienna is definitely keeping pace with the cities you cite. The second phase of the Vienna energy efficiency plan will be launched in 2015. Then there is Aspern Seestadt, where living space is being created for 20,000 people. A living lab has been set up in cooperation with the private sector to study technological developments under realistic conditions. Vienna also has one of the most advanced public transport systems and is seeking to increase the proportion of bicycles. Do you think that there could be resistance to bicycles in a city in which the public transport system works so well?I don't think that public transport and bicycles are in competition. The best cities in the world find solutions to link these two means of transport. Public transport doesn't deliver you door to door. That would be too expensive. Cycling is also useful: the inhabitants of a smart city are healthy. They need to be encouraged to cycle - not to mention the fact that ongoing urbanization puts a strain on public transport capacities.There are cities in which it is impossible to enter the underground at rush hours because it's so full. Cycling is one way of dealing with the massive demand at peak periods.

Complex Subject You are a scientist, university lecturer and writer. Isn't the subject we are talking about too complex? If you ask an average man on the street to explain the concept of a smart city ... ... he couldn't do it.

But what is the problem? Is the subject too elitist?Good question. It's not simple. In my experience you have to present people with subjects in a way that interests them. The key issues are the same all over the world: traffic, environmental pollution or internet access. The approach should therefore be molded into topics that affect people directly and then gradually introduced. In a broader context the solution is then a component of a smart city.

Core Concepts Two of the core concepts are sustainability and innovation. One can encourage but can one coerce?It's always a balancing act. On the one hand citizens should be involved, but on the other there is a need for actions that are good for the future. These two approaches don't always coincide. In Vancouver, where I have lived for some time, I have experienced the discussion on bicycles and cars. The challenge is to do what's best for the city but also to get the support of its inhabitants. Sometimes it doesn't work.

Role of Cities Let's talk about the role of cities in the next decades. Many people move to the city, and in Vienna many of the new arrivals settle in built-up areas outside the city core. What will the role of cities be?It depends on whom you ask. In the United States the suburbs are dying. I read recently that in twenty years the suburbs will be slum areas. Why? Because people ask themselves about their standard of living and note that it drops as they move away from the core. Most people want to be near their work, restaurants and shops. Of course there will always be a few who want to live in the country, but more and more people appreciate what cities have to offer.

You travel all over the world, have checked Vienna and are now here. What do you think of this city?It's beautiful and has fantastic architecture. In general, I'm a fan of European cities and lived a long time in Madrid and Copenhagen. The city has the best possible basis for being regarded as smart. Vienna encourages innovation, has an excellent transport system, a new car-sharing program, great universities and a dynamic middle class. It will continue to play a leading role in Europe. But the competition is hard for the top position. It's fun to watch the developments.